1. Field
The present invention is directed to a light emitting device having a simple structure, and a method of manufacturing the same.
2. Background
A light emitting device generates a light having a certain wavelength when certain voltage and current are applied thereto. Especially, an organic electroluminescent device is self light-emitting device.
FIGS. 1A and 1B are plane views illustrating a light emitting device in the art.
In FIGS. 1A and 1B, the light emitting device comprises anode electrode layers 100, cathode electrode layers 102, sub-pixels 104, walls 108, anode lines 110, cathode lines 112 (112a and 112b), and a driving circuit 114.
The anode electrode layers 100 are disposed in a first direction. The cathode electrode layers 102 are disposed in a second direction different from the first direction.
The sub-pixels 104 are formed on emitting area 120 crossed by the anode electrode layers 100 and the cathode electrode layers 120, and comprise red sub-pixels emitting as red color, green sub-pixels emitting as green color, and blue sub-pixels emitting as blue color. As shown in FIGS. 1A and 1B, a pixel 106 is formed with red sub-pixel, green sub-pixel, and blue sub-pixel disposed in sequence so that the pixel 106 can be generated a light having various colors by combining red, green and blue lights.
The walls 108 are disposed between the cathode electrode layers 102, are made of an insulation material, and electrically divide the cathode electrode layers 102.
The anode lines 110 are connected to the anode electrode layers 100. The cathode lines 112 (112a and 112b) are connected to the cathode electrode layers 102.
The cathode lines 112 may be connected to one end of the cathode electrode layers 102 as shown in FIG. 1A. Also, one part of the cathode lines 112a may be connected to one end of the cathode electrode layers 102, and the other part of the cathode lines 102b may be connected to the other end of the cathode electrode layers 102, as shown in FIG. 1B.
In the driving circuit 114, a scan driver 118a connected to an end of the cathode lines 112 and a data driver 118b connected to an end of the anode lines 110 may be separately construed, as shown in FIG. 1A. Or, the driving circuit 114 may be construed as a driver 116 connected to each end of the lines 110, 112a and 112b, as shown in FIG. 1B.
The driving circuit 114 drives the sub-pixels 104. A detailed explanation thereon will follow in reference to FIG. 2.
FIG. 2 is a circuit view of illustrating the driving process of the light emitting device of FIG. 1B. Here, data lines D1 to D6 correspond to the anode electrode layers 100 and the anode lines 110, and scan lines S1 to S4 correspond to the cathode electrode layers 102 and the cathode lines 112a and 112b. 
In FIG. 2, the driver 116 comprises a controller 200 and a data driver 202.
The controller 200 receives a display data from an outer apparatus (not shown), and controls connection of the scan lines S1 to S4 and the data driver 202 by using the received display data.
The data driver 202 provides data currents corresponding to a first display data and outputted from current sources CS1 to CS6, to the data lines D1 to D6, under control of the controller 200. In this case, a first scan line S1 among the scan lines S1 to S4 is connected to a ground, and the other scan lines S2 to S4 are connected to a non-emitting source having a same voltage (V1) as the driving voltage (Vc) of the light emitting device. Therefore, the data currents flow to the ground through the data lines D1 to D6, the sub-pixels E11 to E61 corresponding to the first scan line S1, and the first scan line S1. As a result, the sub-pixels E11 to E61 emit a light.
Next, the data driver 202 provides data currents corresponding to a second display data inputted to the controller 200 after the first display data, to the data lines D1 to D6, under control of the controller 200. In this case, the second scan line S2 is connected to the ground, and the other scan lines S1, S3 and S4 are connected to the non-emitting source. Thus, only the sub-pixels E12 to E62 corresponding to the second scan line S2 emit a light.
Through a similar process to the above, the sub-pixels E13 to E63 corresponding to the third scan line S3 and the sub-pixels E14 to E64 corresponding to the fourth scan lines S4 emit a light. And, the sub-pixels E11 to E64 repeatedly emit as a unit of the scan lines S1 to S4.
In short, the light emitting device in the art needs to have current sources as many as the data lines D1 to D6 for driving each of the sub-pixels E11 to E64. But, in case of the light emitting device that needs one color or several colors of light only, various colors of light emission is not needed, differently from a case of embodying an image. Thus, in the case, the light emitting device having a complicated structure is inefficient, and the size had to be increased to include many current sources.
The above references are incorporated herein by reference where required for appropriate teachings of additional or alternative details, features and/or technical background.